Primary third eyelid lymphoma with aggressive local behavior in a dog.

Lymphoma is the most common hematopoietic neoplasm in dogs. However, cases primarily involving the third eyelid are rarely reported in the species. The subtype most frequently described in this location is marginal zone lymphoma of the mucosa-associated lymphoid tissue, which has an indolent behavior. A 10-year-old intact female Poodle was presented with a 2-month history of a nodule in the left third eyelid for evaluation. This nodule was surgically excised; however, local recurrence was detected nineteen days postoperatively, with the formation of a mass that expanded and replaced the extraocular orbital tissues and infiltrated the eye. Euthanasia was elected due to the deteriorating clinical condition, and a necropsy was performed. Macroscopically, the mass infiltrated and expanded the eyelids with narrowing of the palpebral fissure, expanded into the orbital space, and infiltrated the cornea and bulbar conjunctiva. Histologically, the mass was composed of sheets of intermediate to large neoplastic lymphocytes, with frequent epitheliotropism and tingible bodies. Neoplastic lymphocytes were immunoreactive for PAX5, CD20, and CD79a and were not immunoreactive for CD3. The neoplasm was restricted to the left eyelid and orbit. A diagnosis of primary third eyelid lymphoma (extranodal) with immunophenotype B and locally aggressive behavior was made based on the macroscopic, histological, and immunohistochemical findings.

Pasteurella multocida polyserositis in growing-finishing pigs.

Pasteurella multocida is the main secondary bacterium isolated from cases of swine pneumonia. Although highly pathogenic strains of P. multocida have been associated with primary septic lesions and polyserositis in pigs, studies on this pathological presentation in naturally occurring cases are limited. The aim of this work was to characterize the clinical, pathological and molecular findings in cases of P. multocida polyserositis in growing-finishing pigs in a commercial farm in Brazil. The mean age of 17 investigated pigs was 120 days. Clinically, the disease was acute (11/17), with clinical signs of dyspnoea and apathy. Sudden death occurred in some animals (6/17). The main gross findings included fibrinous serositis affecting the abdominal and thoracic cavities (17/17), fibrinous pericarditis (15/17), marked cranioventral pulmonary consolidation (17/17) and splenic infarcts (3/17). P. multocida was isolated in all cases from systemic sites, including the pericardial sac and abdominal exudate. Molecular typing of genus and species was performed on four isolates, and all were characterized as P. multocida type A. Another five isolates were positive for the pathogenicity marker gene pfhA by polymerase chain reaction. This study reinforces the role of P. multocida as a cause of polyserositis in growing-finishing pigs.

Ophthalmic and immunopathological characterization of systemic infectious diseases in cats.

Ocular involvement in systemic diseases is frequent in cats; however, without concurrent clinical and ophthalmic examinations with gross and/or histologic analysis of the eye, these findings can be underdiagnosed. This article aims to provide gross, histologic, and immunohistochemical characteristics of ocular lesions from cats submitted to necropsy, focusing on those caused by systemic infectious agents. Cats that died due to a systemic infectious disease were selected based on necropsy diagnosis and presence of ocular lesions. Gross, histologic, and immunohistochemical findings were recorded. From April 2018 to September 2019, 849 eyes of 428 cats were evaluated. Histologic abnormalities were seen in 29% of cases, which were classified as inflammatory (41%), neoplastic (32%), degenerative (19%), and metabolic/vascular (8%). Macroscopic changes were present in one-third of eyes with histologic lesions. Of these, 40% were attributed to inflammatory or neoplastic diseases associated with infectious agents. The most important infectious agents causing ocular disease in this study were feline leukemia virus, feline infectious peritonitis virus, and Cryptococcus sp. The most common ocular abnormalities associated with infectious agents were uveitis (anterior, posterior, or panuveitis), optic neuritis, and meningitis of the optic nerve. Ocular lesions secondary to systemic infections in cats are frequent; however, these are not always diagnosed because gross lesions are less common than histologic lesions. Therefore, both gross and histologic evaluation of the eyes of cats is recommended, mainly for cases in which the clinical suspicion or necropsy diagnosis suggests that an infectious agent might be related to the cause of death.

Motor and somatosensory degenerative myelopathy responsive to pantothenic acid in piglets.

This report describes 2 events of degenerative myelopathy in 4- to 27-day-old piglets, with mortality rates reaching 40%. Sows were fed rations containing low levels of pantothenic acid. Piglets presented with severe depression, weakness, ataxia, and paresis, which were more pronounced in the pelvic limbs. No significant gross lesions were observed. Histologically, there were degeneration and necrosis of neurons in the spinal cord, primarily in the thoracic nucleus in the thoracic and lumbar segments, and motor neurons in nucleus IX of the ventral horn in the cervical and lumbar intumescence. Minimal-to-moderate axonal and myelin degeneration was observed in the dorsal funiculus of the spinal cord and in the dorsal and ventral nerve roots. Immunohistochemistry demonstrated depletion of acetylcholine neurotransmitters in motor neurons and accumulation of neurofilaments in the perikaryon of neurons in the thoracic nucleus and motor neurons. Ultrastructurally, the thoracic nucleus neurons and motor neurons showed dissolution of Nissl granulation. The topographical distribution of the lesions indicates damage to the second-order neurons of the spinocerebellar tract, first-order axon cuneocerebellar tract, and dorsal column-medial lemniscus pathway as the cause of the conscious and unconscious proprioceptive deficit, and damage to the alpha motor neuron as the cause of the motor deficit. Clinical signs reversed and no new cases occurred after pantothenic acid levels were corrected in the ration, and piglets received parenteral administration of pantothenic acid. This study highlights the important and practical use of detailed neuropathological analysis to refine differential diagnosis.

Eosinophilic Granulomatous Myocarditis in Two Pigs.

Eosinophilic myocarditis is a human condition that has been rarely documented in animals. We now report two unrelated porcine cases of idiopathic eosinophilic granulomatous myocarditis that resembled the human disease and which were associated with sudden death. The most relevant gross finding in both cases was marked cardiomegaly, accompanied by raised, multifocal to coalescent small white nodules (1-2 mm) and poorly demarcated multifocal pale areas in the epicardium. Histologically, there were multifocal to coalescent areas of cardiomyocyte loss with replacement by an intense inflammatory infiltrate of eosinophils and epithelioid macrophages, and proliferation of fibrous connective tissue. Immunohistochemistry for porcine circovirus type 2 (PCV2) and Toxoplasma gondii, in-situ hybridization and quantitative polymerase chain reaction tests for PCV2 and porcine circovirus type 3 and aerobic bacterial culture on myocardium samples were negative.

Pathology in Practice.

In collaboration with the American College of Veterinary Pathologists.

Duodenal leiomyosarcoma in a cat: Cytologic, pathologic, and immunohistochemical findings.

A 7-year-old mixed-breed neutered male cat was presented with a history of chronic vomiting with increased frequency in the last month, progressing to depression and profuse projectile vomiting. Abdominal ultrasonography revealed an area of marked segmental duodenal thickening associated with a nodule, and euthanasia was performed due to a poor prognosis. Grossly, at the postmortem examination, the wall of a duodenal segment was severely expanded by a nodule measuring 5.0 cm in diameter, resulting in marked luminal narrowing and obstruction. Smears were made by scraping the cut surface of the tumor during the postmortem examination. The smears were highly cellular and contained mesenchymal cells arranged individually or in large non-cohesive aggregates. Cells varied in morphology from spindle to round to stellate-shaped with marked anisocytosis and anisokaryosis. Numerous bi- and multinucleated neoplastic cells were observed. Histologic examination revealed a densely cellular neoplastic proliferation of mesenchymal cells that effaced the duodenal submucosa, muscularis externa, and serosa layers. Most cells were spindle-shaped; however, some tumor areas had numerous round cells and bi- and multinucleated neoplastic cells. Spindle cells showed variable cytoplasmic immunoreactivity for vimentin, smooth muscle actin, and desmin. Round, bi-, and multinucleated giant cells only had marked multifocal cytoplasmic immunoreactivity for vimentin. Neoplastic cells did not have immunoreactivity for cytokeratin, GFAP, S100, and CD117. A final diagnosis of duodenal leiomyosarcoma was made. This article reports the pathologic, cytologic, and immunohistochemical findings of this case and discusses the main differential diagnoses in cases of intestinal sarcomas in domestic animals.

An outbreak of visna-maedi in a flock of sheep in Southern Brazil.

Visna-maedi is a multisystemic and progressive inflammatory disease caused by a non-oncogenic retrovirus (Visna-maedi virus, VMV). An outbreak of visna-maedi occurred in Southern Brazil in sheep with clinical signs of blindness and stumbling gait. At post-mortem examination, all animals had similar lesions, including heavy non-collapsed lungs and multifocal yellow areas in the cerebral white matter, affecting mainly the periventricular region. These lesions corresponded histologically to lymphocytic interstitial pneumonia and histiocytic periventricular encephalitis surrounding areas of necrosis, in addition to significant demyelination in the brain. Serology was performed in all the sheep from the flock and 14% were seropositive for VMV. The presence of VMV was confirmed through PCR and partial sequencing of the 5'LTR. Sequencing demonstrated that the virus had 89.7 to 90.0% of nucleotide identity with VMV strains reported in the USA. This is the first description of clinical disease related to VMV in Brazil leading to economic losses. This study calls for the need to implement control measures to prevent the spread of small ruminant lentiviruses in Brazil.

Wischnewski Spots and Black Oesophagus in Suspected Fatal Hypothermia in a Brown Howler Monkey (Alouatta guariba clamitans) and a Rabbit (Oryctolagus cuniculus).

Fatal hypothermia represents a diagnostic challenge in veterinary pathology. Wischnewski spots (WS) and black oesophagus (BO) have been described in human cases of fatal hypothermia but rarely in animals. We now describe WS and BO in suspected fatal hypothermia in a free-ranging brown howler monkey (Alouatta guariba clamitans) and a pet rabbit (Oryctolagus cuniculus). Both animals had dark spots resembling WS on the gastric mucosa and the monkey also had BO with haematin deposition. In both cases, stress factors and relatively cold environmental conditions were present prior to death.

Mucinous Rectal Adenocarcinoma in a Urutu Snake (Bothrops alternatus).

A 15-year-old captive female Urutu snake (Bothrops alternatus) was presented with anorexia, apathy, dehydration, pale mucous membranes and marked enlargement of the caudal third of the coelomic cavity. Radiographs and ultrasonography were suggestive of faecal impaction or neoplasia. Post-mortem findings consisted of solid faecal impaction of the intestines, secondary to obstruction caused by a rectal tumour. Cytological examination of impression smears of the tumour revealed polygonal to round neoplastic cells arranged in clusters in an abundant extracellular mucinous matrix. Histologically, there was transmural growth of neoplastic epithelial cells arranged in small nests or individually and immersed in abundant extracellular mucin lakes. The neoplastic cells were immunopositive for cytokeratin. Clinical and pathological aspects indicated a diagnosis of mucinous rectal adenocarcinoma.

Pathology of Gastrointestinal Tuberculosis in Cattle.

We describe the pathology of gastrointestinal tuberculosis in three cows. Gross lesions were found in the jejunum and ileum in all cases, and were characterized by button-shaped ulcers in the mucosa overlying Peyer's patches and adjacent mucosa. One case had similar changes in the pyloric region of the abomasum. In the affected intestinal segments, marked granulomatous inflammation effaced the lymphoid follicles of Peyer's patches and often extended transmurally. Transmural granulomatous inflammation was also found in the abomasum of one cow. Acid-fast bacilli were identified by the Ziehl-Neelsen method and the lesions were immunolabelled by an anti-Mycobacterium tuberculosis complex antibody. M. tuberculosis var. bovis was isolated in one case. Disseminated tuberculosis and marked lung lesions in all cows suggested that the gastrointestinal lesions were most likely secondary to pulmonary infection.

A new highly divergent copiparvovirus in sheep.

The subfamily Parvovirinae within the family Parvoviridae consists of viruses that can infect a wide range of vertebrate hosts and cause effects ranging from severe disease to asymptomatic infection. In the present study, high-throughput sequencing (HTS) was utilized to analyze samples obtained from an abortion outbreak in a sheep flock to identify a putative viral etiology. A highly divergent nearly complete parvovirid genome sequence, approximately 4.9 kb in length, was determined. The nonstructural protein (NS1) amino acid (aa) sequence of this virus shared less than 30% identity with those of other copiparvoviruses and less than 22% identity with those of members of other genera in the subfamily Parvovirinae. Phylogenetically, this virus, which we have provisionally named "sheep copiparvovirus 1", formed a cluster with copiparvovirus sequences and should be classified as a member of a new species in the genus Copiparvovirus.

Causes of death in sheep in Rio Grande do Sul, Brazil: analysis of 523 cases (2004-2019) / Causas de morte em ovinos no Sul do Brasil: análise de 523 casos (2004-2019)

The increase in the commercialization of sheep products requires an equivalent improvement in flock health and rapid disease identification. Data regarding the cause of death in sheep were reviewed from the database of the "Setor de Patologia Veterinária" from the "Universidade Federal do Rio Grande do Sul", from January 2004 and December 2019. Epidemiological features, such as breed, sex, and age, in addition to the clinical and pathological features, were analyzed. During this period, tissues from 523 sheep were evaluated, in which a conclusive diagnosis was obtained in 457 (87%) of the cases. The majority of sheep were from the metropolitan mesoregion of Porto Alegre. The most common breed was Texel 171/523 (33%). From all the conclusive diagnoses, 158/457 (35%) corresponded to infectious non-parasitic diseases, 117/457 (26%) were caused by toxic etiology, 95/457 (21%) were infectious parasitic diseases, 42/457 (9%) were included in the nutritional and metabolic category, 38/457 (8%) were in the "others" category, and 7/457 (1.5%) were congenital defects. The age of sheep included in this study ranged from 1 day to 7 years. Among cases with conclusive diagnosis, the main cause of death was haemonchosis with 83/457 (18%) of cases, followed by pneumonia 29/457 (6%), Baccharis sp. poisoning 25/457 (5%), and bluetongue 22/457 (5%).(AU)

O aumento da comercialização de produtos ovinos requer um aumento equivalente na sanidade do rebanho e uma rápida identificação de doenças. Os dados sobre as causas de morte em ovinos foram revisados no banco de dados do Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul, entre janeiro de 2004 e dezembro de 2019. Aspectos epidemiológicos, como raça, sexo e idade, além das características clínicas e patológicas, foram compilados. Nesse período, foram avaliados tecidos de 523 ovinos, em que o diagnóstico conclusivo foi obtido em 457 (87%) dos casos. A grande maioria dos ovinos era da mesorregião metropolitana de Porto Alegre. A raça mais comum foi Texel 171/523 (33%). De todos os diagnósticos conclusivos, 158/457 (35%) corresponderam a doenças infecciosas não-parasitárias, 117/457 (26%) foram causadas por doenças tóxicas, 95/457 (21%) doenças infecciosas parasitárias, 42/457 (9%) foram incluídos na categoria nutricional e metabólica, 38/457 (8%) foram classificadas na categoria "outros", e 7/457 (1,5%) eram defeitos congênitos. A faixa etária das ovelhas incluídas neste estudo foi de um dia a sete anos de idade. Entre os casos com diagnóstico conclusivo, a principal causa de óbito foi hemoncose com 83/457 (18%) dos casos, seguida de pneumonia 29/457 (6%), intoxicação por Baccharis sp. 25/457 (5%), e infecção pelo vírus da língua azul 22/457 (5%).(AU)

Causes of death in sheep in Rio Grande do Sul, Brazil: analysis of 523 cases (2004-2019)

ABSTRACT: The increase in the commercialization of sheep products requires an equivalent improvement in flock health and rapid disease identification. Data regarding the cause of death in sheep were reviewed from the database of the Setor de Patologia Veterinária from the Universidade Federal do Rio Grande do Sul, from January 2004 and December 2019. Epidemiological features, such as breed, sex, and age, in addition to the clinical and pathological features, were analyzed. During this period, tissues from 523 sheep were evaluated, in which a conclusive diagnosis was obtained in 457 (87%) of the cases. The majority of sheep were from the metropolitan mesoregion of Porto Alegre. The most common breed was Texel 171/523 (33%). From all the conclusive diagnoses, 158/457 (35%) corresponded to infectious non-parasitic diseases, 117/457 (26%) were caused by toxic etiology, 95/457 (21%) were infectious parasitic diseases, 42/457 (9%) were included in the nutritional and metabolic category, 38/457 (8%) were in the others category, and 7/457 (1.5%) were congenital defects. The age of sheep included in this study ranged from 1 day to 7 years. Among cases with conclusive diagnosis, the main cause of death was haemonchosis with 83/457 (18%) of cases, followed by pneumonia 29/457 (6%), Baccharis sp. poisoning 25/457 (5%), and bluetongue 22/457 (5%).

RESUMO: O aumento da comercialização de produtos ovinos requer um aumento equivalente na sanidade do rebanho e uma rápida identificação de doenças. Os dados sobre as causas de morte em ovinos foram revisados no banco de dados do Setor de Patologia Veterinária da Universidade Federal do Rio Grande do Sul, entre janeiro de 2004 e dezembro de 2019. Aspectos epidemiológicos, como raça, sexo e idade, além das características clínicas e patológicas, foram compilados. Nesse período, foram avaliados tecidos de 523 ovinos, em que o diagnóstico conclusivo foi obtido em 457 (87%) dos casos. A grande maioria dos ovinos era da mesorregião metropolitana de Porto Alegre. A raça mais comum foi Texel 171/523 (33%). De todos os diagnósticos conclusivos, 158/457 (35%) corresponderam a doenças infecciosas não-parasitárias, 117/457 (26%) foram causadas por doenças tóxicas, 95/457 (21%) doenças infecciosas parasitárias, 42/457 (9%) foram incluídos na categoria nutricional e metabólica, 38/457 (8%) foram classificadas na categoria outros, e 7/457 (1,5%) eram defeitos congênitos. A faixa etária das ovelhas incluídas neste estudo foi de um dia a sete anos de idade. Entre os casos com diagnóstico conclusivo, a principal causa de óbito foi hemoncose com 83/457 (18%) dos casos, seguida de pneumonia 29/457 (6%), intoxicação por Baccharis sp. 25/457 (5%), e infecção pelo vírus da língua azul 22/457 (5%).

Fibrinonecrotic Placentitis and Abortion Associated With Pantoea agglomerans Infection in a Mare.

Pantoea agglomerans, family Enterobacteriaceae, is a Gram-negative bacterium that may be isolated from soil and from plants. This bacterium has been associated with disease in plants, humans, and rarely in domestic animal species. We describe here a case of fibrinonecrotic placentitis and equine abortion associated with P. agglomerans infection in southern Brazil. A fetus with 10 months of gestation and its placenta were evaluated. Gross lesions were observed in the cervical star extending to the body of the chorioallantois and consisted of a focally extensive, transmural, severely thickened yellow area. Histologically, this area in the chorioallantois was effaced by severe necrosis, associated with marked inflammatory infiltrate of neutrophils and abundant deposition of fibrin and cellular debris. Aggregates of bacterial rods were noted intermixed with inflammation areas. No significant lesions were observed in the remaining organs inspected. Tissue samples of the lung, placenta, and stomach contents were cultured, and microbiological tests revealed the growth of P. agglomerans in all evaluated samples. The present study reaffirms the participation of P. agglomerans as a cause of bacterial placentitis and abortion in horses.

Epidemiological, pathological and immunohistochemical aspects of 125 cases of feline lymphoma in Southern Brazil.

A retrospective study compiling cases of feline lymphoma diagnosed during 12 years (2004-2016) in Southern Brazil was performed. A total of 125 cases of lymphoma diagnosed in cats were reviewed, and information including age, breed, sex and tumour topography were collected. FeLV and FIV immunohistochemical tests were performed, as well as immunophenotyping of lymphomas. The alimentary form represented the most common presentation (42/125), followed by mediastinal lymphoma (35/125). Out of 125 cases, 79 presented positive retroviral immunostaining in tumour tissue (52 FeLV alone, 14 FIV alone and 13 presented FIV and FeLV co-infections), 66/125 of the cases were of T-cell origin and 59/125 of the cases were of B-cell origin. The median age of cats with T-cell lymphoma was 120 months (10-240 months), and 60 months (6-204 months) for cats with B-cell lymphoma. The most frequent alimentary tumour presentation was the enteropathy-associated T-cell lymphoma (type 1), and the major type of mediastinal tumour observed was diffuse large B-cell lymphoma. Considering only mediastinal and alimentary lymphomas (n = 77), the prevalence of mediastinal lymphoma in FeLV-positive cats was 2.21 times higher than the prevalence of this type of tumour in FeLV-negative cats (P = .036). Mediastinal lymphoma was more frequently observed in younger cats, and the prevalence of mediastinal tumours in these animals was 3.06 times higher than the prevalence of this tumour form in old cats (P = .0125). The present study indicates that retroviral infections still play an important role in the development of feline lymphomas in southern Brazil.

The feline cutaneous and oral microbiota are influenced by breed and environment.

Previous research revealed the feline skin bacterial microbiota to be site-specific and the fungal microbiota to be individual-specific. The effect of other factors, such as genotype and environment, have not yet been studied in cats, but have been shown to be potentially important in shaping the cutaneous microbiota of other animals. Therefore, the objectives of this study were to evaluate the effect of these factors on the bacterial and fungal microbiota of feline skin and oral cavity. The influence of genotype was assessed through the analysis of different cat breeds, and the influence of environment through comparison of indoor and outdoor cats. DNA was extracted from skin and oral swabs, and bacterial and fungal next-generation sequencing were performed. Analysis of the skin microbiota of different cat breeds revealed significant differences in alpha diversity, with Sphynx and Bengal cats having the most diverse communities. Many taxa were found to be differentially abundant between cat breeds, including Veillonellaceae and Malassezia spp. Outdoor environment exposure had considerable influence on beta diversity, especially in the oral cavity, and resulted in numerous differentially abundant taxa. Our findings indicate that the oral bacterial microbiota and both fungal and bacterial microbiota of feline skin are influenced by breed, and to a lesser degree, environment.